This invention relates to a memory card which houses a semiconductor device and more particularly, to a memory card having an improved plastic outer package which enables the memory card to be manufactured more easily and cheaply than a conventional memory card.
In recent years, external memory devices have been developed which comprise a thin, card-like, plastic outer package which houses a semiconductor device and an electrical connector for electrically connecting the semiconductor device to external equipment. These memory devices, which will be referred to hereinunder as memory cards, have found widespread use as storage devices for data and programs for video games and microcomputers. FIG. 1 is a perspective view of a conventional memory card of the type to which the present invention pertains, FIGS. 2 and 3 are respectively a top and a bottom view thereof, and FIG. 4 is a longitudinal cross-sectional view of the left end of the memory card of FIG. 1. As shown in these figures, a conventional memory card has a plastic outer package consisting of an upper package section 1 and a lower package section 2 which are stacked atop one another. The two package sections surround and protect an internal base 3 which has an unillustrated semiconductor device mounted thereon. The outer package has a rectangular cavity at its front end into which an electrical connector 7 is inserted. The connector 7 has a plurality of sockets formed therein which are electrically connected to the unillustrated semiconductor device on the internal base 3 by leads 4 and 5, which are connected to the internal base 3 by solder 6.
A conventional memory card of this type is assembled by first disposing the internal base 3 and the connector 7 inside the lower package section 2 and then combining the upper package section 1 with the lower package section 1. Due to the clearances between the various parts which are necessary for assembly, gaps 8 are inevitably produced between the rear end of the connector 7 and the front portions of the package sections 1 and 2. The memory card at this stage of assembly appears as shown in FIGS. 2 and 3. If these gaps 8 were not filled, not only would the electrical leads 4 and 5 be visible through the gaps 8, but it would be possible for dirt and other contaminants to enter into the outer package through the gaps 8, produce electrical shorts, and damage the semiconductor device mounted on the internal base 3. Furthermore, as the distance from the outer surfaces of the leads 4 and 5 to the outer surfaces of the package sections 1 and 2 and the internal base 3 is quite small, the semiconductor device which is mounted on the internal base 3 could be damaged by static electricity. For this reason, at the time of assembly, an electrically-insulating resin 9 is applied around the periphery of the leads 4 and 5 to insulate the leads and fill the gaps 8. On account of the need to apply this resin 9, material costs and the complexity of the assembly process are increased, resulting in increased manufacturing costs.